Why we acted
Our community garden strives both ethically and financially as role models for the community and when water usage grew we knew we had to find out why.
During the 12 month period 2013–14 the garden used almost 1,800 kilolitres which was triple the 600 kilolitres typically used. This also had financial ramifications of tripling the normal water bill up to $3,600.
The increased usage was attributed in part to an underground leak which went undetected for several months.
Since addressing the leak and implementing water efficiency measures, usage is back to around 600 kilolitres per annum and the bill for 2014–15 was reduced to $1,200.
The garden is a not-for-profit group operating on a modest budget. A water account triple the normal budget places serious pressure on the operating future of the club.
How we did it
As water use at the garden was unmonitored and vulnerable to unscheduled use, a data logger was installed in February 2014.
The logger monitors water use 24/7 and was set up to send alarms when a daily water use limit is exceeded and sent weekly graphs of the water usage.
The graph provides a quick interrogation of use for the past week. Use shows as spikes creating a usage fingerprint for scheduled water use when the tap timers come on. Unscheduled use such as a leak or hand watering can be clearly distinguished and is measurable.
Graphs are frequently sent to the members to keep them in the loop to demonstrate the amount of water used each day and of any unscheduled water use.
Data logger alarms were able to identify and address unscheduled water use habits and significant unscheduled use. This assisted with an unscheduled use in April 2015 which was due to a mistake with programming of a retic timer unit.
We installed a CSIRO fullstop unit which is a wetting front detector which helped us to work out the volume of water to apply to water deep enough to encourage deeper roots but not past the root zone to leach nutrients.
A tensionometer installed on a garden bed visually shows how hard the vegetables are working to extract moisture from the soil to help set irrigation or when additional hand watering is necessary and is used in conjunction with drip irrigation which is more efficient than surface irrigation.
The City of Stirling provided financial support to implement a number of Waterwise initiatives. This included organising a water efficiency audit to identify changes that could be made to reduce water use, purchasing materials and sourcing recycled shade cloth to allow the construction of shade structures over each garden bed, and providing free mulch.
We also operate a large-scale composting system on site and this compost is added to our garden beds along with bentonite clay to further improve the water holding capacity of our soil.
- Fullstop unit
- 3G Data logger
- Tensionometer (GDoT)
- DAFWA soil moisture app
- Shade structure
- Mulch from City of Stirling or MulchNet
What we are doing now
The garden aims to further improve water efficiency and safeguard against unscheduled usage to reduce consumption even further.
The garden has sought help from Department of Agriculture and Food (DAFWA) who recently released a mobile app to guide water usage based on crop type and its growth stage, soil type, irrigation system and climate.
In applying water rates suggested by the app:
- the irrigation system operation and set-up will be checked by irrigation specialists, Elliots
- further testing will be done to improve soil moisture holding capacity
- the purchase of new moisture testing equipment and GDot tensionometers will help to position in more plots.
Workshops to educate garden members and share lessons learnt onto the broader community are proposed.
We will also purchase and install Aquatrip, a low cost valve (about $200) which shuts off water should usage exceed a set period of time (eg longer than any expected usage).
Department of Agriculture and Food Growth APP
Who to contact
If you would like more information on water efficiency in your business please email us.